The U.S. Centers for Disease Control and Prevention (CDC) director on Tuesday signed off on the broad use of updated COVID-19 vaccines approved by the government, covering ages six months and up, as the country prepares to start a vaccination campaign within days.

The final recommendation from director Mandy Cohen comes after a panel of advisers to the agency voted 13-1 to recommend the shots made by Pfizer, partner BioNTech SE and Moderna.

They did not choose to target the shots at specific high-risk populations as some experts have suggested and other countries have recommended. The shots are part of a push by public health officials to align the next COVID-19 vaccines more closely with the actual circulating variant of the virus, much as annual flu shots are designed.

The recommendation differs from those in most European countries that have issued guidance. This month, the European Centre for Disease Prevention and Control (ECDC) said vaccination programs in EU countries should prioritize people aged 60 and older and other vulnerable groups.

In Germany, booster shots have targeted these groups. However, the British government's vaccine committee said only adults 65 and older and some other categories will be offered the shot as they are the most likely to benefit.

U.S. CDC panel members said simply recommending the vaccine for everybody outweighed complications created by tailoring recommendations more precisely.

"I'm strongly in favor of a universal recommendation," panel member and professor at Harvard Medical School Dr. Camille Kotton said. "Let's do away with COVID-19 as best we can by prevention of disease through vaccines."

Is it suitable for broad recommendation?

William Schaffner, an infectious disease specialist at Vanderbilt University, said, "Acceptability, feasibility, clarity, and simplicity are the dominant issues," Science reported. 

"I hope we make it as acceptable as possible. Don't think about it, just get it."

This method might encourage more people to get boosters, and the benefits for those least vulnerable, even if modest, might still outweigh the risks. 

Schaffner stressed that SARS-CoV-2 can cause serious illness for every age group, even in people who do not have risk factors.  "We ought to open up this accordion and make it as similar to the flu vaccine as possible." 

"The more we make it a social norm for everyone to do, perhaps we will get beyond some of this vaccine ennui, vaccine hesitancy, and the political aspects that still surround these decisions," he said. 

Could my booster potentially protect others?

Possibly, but not for a long period, the Science reported. 

A booster might lower the viral load in people who become infected, reducing what they shed. 

Jennifer Nuzzo, an epidemiologist who heads the Pandemic Center at Brown University, suggested that "you might want to time that booster so that you have that peak level of protection when you're going to see your elderly relatives." 

Vaccine experts agree that booster shots will help those most vulnerable, but there's little consensus about who else will benefit from them. 

"I know that some of my colleagues have different opinions, and they're trying to be as thoughtful as I am," Schaffner said. "I don't think there's one easy, correct, best answer."

(With input from Reuters)